1. Field of the Invention
The present invention relates to an audio/video bridging (AVB) system using an extended AVB reservation protocol and a method of reserving a resource. More particularly, the present invention relates to an AVB system which can perform a registration process or a reservation process without an additional request or an extension of an upper layer application by using an application stream identifier corresponding to the upper layer application, and a method of reserving a resource.
2. Description of Related Art
An audio/video bridging (AVB) technology generally indicates a technology which provides streaming services with a comparatively smaller delay in an Institute of Electrical and Electronics Engineers (IEEE) 802 network using a time-synchronization. The AVB technology may utilize a stream reservation protocol which secures a resource in a bridge for an audio/video stream.
Currently, an AVB reservation protocol includes an egress device to start a registration process based on a Generic Attribute Registration Protocol (GARP) or Multiple Registration Protocol (MRP) of an IEEE 802.1 standard and an ingress device to start an admission control process.
The egress device utilizes a GARP/MRP registration/deregistration to ensure its intention of joining a stream transmission. With this operation, the ingress device and a relay device will know where potential egress devices are and how to acquire information about the egress devices.
Also, the ingress device transmits a reservation signal to the egress device and performs admission control and resource reservation for the above-described stream transmission.
An AVB reservation protocol is generally triggered and used by an upper layer application, such as an RSVP, a Universal Plug and Play Audio/Video (UPnP AV), a Universal Plug and Play Quality of Service (UPnP QoS), and the like. Therefore, an interface method between the AVB reservation protocol and the upper layer application is required.
FIG. 1 is a diagram illustrating an AVB system using an AVB reservation protocol according to a conventional art.
As described above, the AVB reservation protocol corresponds to a layer 2 (L2) reservation protocol which is triggered by an upper layer application 101. The AVB reservation protocol may configure a filtering database 103 that has an L2 stream identifier 102.
The AVB reservation protocol currently requires both an egress device 104 and an ingress device 105 to be aware of an AVB stream identifier corresponding to an L2 reservation protocol. The AVB stream identifier may be in a format compatible with a current bridge forwarding mechanism to enable efficient data forwarding. A current proposal is to use a 48-bit MAC address.
AVB stream identifiers are generally allocated by the ingress device 105 and known to the egress device 104. However, the AVB reservation protocol is not involved in conveying the AVB stream identifier between the egress device 104 and the ingress device 105 and the conveying is performed by the upper layer application 101 that triggers the AVB reservation protocol.
As described above, in the conventional art, a conveyance between an ingress device and an egress device with respect to information regarding the AVB stream identifier is performed by a standardized upper layer application and thus a protocol of performing the conveyance may not be readily extended. For example, while RSVP can be used to reserve resources in an Internet Protocol (IP) layer, RSVP should trigger an AVB reservation protocol to reserve a resource corresponding to a layer associated with the AVB reservation protocol. However, the RSVP does not have a capability to convey information regarding the AVB stream identifier between the egress device and the ingress device. Specifically, as described above, the RSVP may not transmit the AVB stream identifier allocated by the ingress device to the egress device.
To overcome the above-described disadvantages, an AVB stream identifier of an ingress device may be transmitted to an egress device by adding a new signal to an AVB reservation protocol, which may incur an additional signaling overhead and stream setup latency.
Accordingly, there is a need for an AVB system using an extended AVB reservation protocol and a reservation method.